replace() in Python to replace a substring

Given a string str that may contain one more occurrences of “AB”. Replace all occurrences of “AB” with “C” in str.


Input  : str = "helloABworld"
Output : str = "helloCworld"

Input  : str = "fghABsdfABysu"
Output : str = "fghCsdfCysu"

This problem has existing solution please refer Replace all occurrences of string AB with C without using extra space link. We solve this problem in python quickly using replace() method of string data type.

How does replace() function works ?
str.replace(pattern,replaceWith,maxCount) takes minimum two parameters and replaces all occurrences of pattern with specified sub-string replaceWith. Third parameter maxCount is optional, if we do not pass this parameter then replace function will do it for all occurrences of pattern otherwise it will replace only maxCount times occurrences of pattern.





# Function to replace all occurrences of AB with C
def replaceABwithC(input, pattern, replaceWith):
    return input.replace(pattern, replaceWith)
# Driver program
if __name__ == "__main__":
    input   = 'helloABworld'
    pattern = 'AB'
    replaceWith = 'C'
    print replaceABwithC(input,pattern,replaceWith)



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